Asynchronous programming has been around for several years on the .NET platform but has historically been very difficult to do well. Since the introduction of async/await in C# 5 asynchronous programming has become mainstream. Modern frameworks (like ASP.NET Core) are fully asynchronous and it’s very hard to avoid the async keyword when writing web services. As a result, there’s been lots of confusion on the best practices for async and how to use it properly. This section will try to lay out some guidance with examples of bad and good patterns of how to write asynchronous code.